The black box of the Indian Air Force’s An-32 that crashed in Arunachal Pradesh on June 3 killing 13 military personnel has been found, according to news agency ANI.

The retrieval of the black box raises hopes that the air force would be able to establish the sequence of events moments before An-32, considered the IAF’s workhorse, smashed into Arunachal’s Pari-Adi mountain range.

An Indian Air Force official said the recee team that had been able to reach the wreckage on Thursday morning had been able to retrieve the flight data recorder, or FDR, and the cockpit voice recorder, or CVR that make up for the black box.

The CVR is designed to primarily record the flight crew’s voices but is also helpful for investigators to correlate information from other sources with other ambient sounds such as engine noise and stall warnings. The flight recorder tracks scores of characteristics related to the plane including altitude, airspeed and even the flap position.

The two recorders that make up for the black box are enclosed in an orange-coloured steel compartment mounted in the tail of the aircraft.

The AN-32 took off from Jorhat in Assam on June 3 and was on its way to an advanced landing ground at Mechuka in Arunachal Pradesh’s West Siang district when it lost contact with ground control.

Over the next week, helicopters and planes scoured hundreds of square miles of the mountainous region before rescue workers received a clue about a possible location of the wreckage. It was on a mountainside at an elevation of some 12,000 feet. A mountaineering team trekked to the crash spot after being air dropped at a nearby location after two failed attempts.

“Eight members of the rescue team have reached the crash site today (Thursday) morning. IAF is sad to inform that there are no survivors,” the air force tweeted.